Pi-hole FTL v4.2.3 #519
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Pi-hole FTL v4.2.3 #519
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Signed-off-by: Mcat12 <newtoncat12@yahoo.com> Signed-off-by: DL6ER <dl6er@dl6er.de> Conflicts: shmem.c
…t that at least one of the objects has changed Signed-off-by: DL6ER <dl6er@dl6er.de>
Signed-off-by: DL6ER <dl6er@dl6er.de>
…ory objects into all running processes, even if they are forks Signed-off-by: DL6ER <dl6er@dl6er.de>
Signed-off-by: DL6ER <dl6er@dl6er.de>
…a new virtual address Signed-off-by: DL6ER <dl6er@dl6er.de>
Signed-off-by: DL6ER <dl6er@dl6er.de>
This was causing an issue because each process had a different value for the next string position, and caused corruption in the string shared memory. Signed-off-by: Mcat12 <newtoncat12@yahoo.com>
The version on development is 3, so this version should be 4. Signed-off-by: Mcat12 <newtoncat12@yahoo.com>
AzureMarker
reviewed
Feb 22, 2019
| close(fd); | ||
| // needed after having called ftruncate() | ||
| if(resize) | ||
| close(fd); |
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The file descriptor could be closed at the end of the first if block where we resize the memory, instead of waiting until here to close it. It's only used in a logging statement outside of the if block (and doesn't need to be there).
AzureMarker
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Feb 22, 2019
dschaper
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Feb 24, 2019
diginc
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Feb 24, 2019
PromoFaux
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jacobsalmela
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Feb 25, 2019
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This release fixes #496
Issue
DNS requests and responses can happen over UDP or TCP. UDP is the most common, but TCP is used often for large responses or by some specific products (we have seen this with Netflix in the past). Handling TCP connections requires more communication with the client and server, so
pihole-FTLcreates TCP helper processes by forking.When dynamically allocated shared memory objects get resized, they get resized, and then re-mapped. The problem is that if our shared memory object is now significantly larger and if this happens on a TCP handler process, the other processes were not notified about the virtual memory change keep using the old shared memory, i.e., they were using dangling pointers. This caused a memory corruption or access error when accessed.
Solution
This pull requests ensures that, when the space of virtual addresses changes, the other forks get notified and can re-map the shared memory objects to get possibly updated virtual memory addresses for their pointers.